fix deleting note from task manager, closes #3239

src/becca/entities/branch.js

@@ -170,6 +170,10 @@ class Branch extends AbstractEntity {
 
             log.info("Deleting note " + note.noteId);
 
+            // marking note as deleted as a signal to event handlers that the note is being deleted
+            // (isDeleted is being checked against becca)
+            delete this.becca.notes[note.noteId];
+
             for (const attribute of note.getOwnedAttributes()) {
                 attribute.markAsDeleted(deleteId);
             }